The present invention relates to the trucking industry and more specifically to tarp systems that can be used for covering flatbeds on trucks and trailers. In particular, this invention relates to a bracket assembly that is used to assemble modular bows in a sliding tarp system and to methods of assembling the same.
Trucks and trailers that have flatbeds are used to transport a wide variety of freight, most of which cannot be loaded into conventional van-type trucks or trailers having walls and a roof. In order to protect the shipped goods from exposure to the outside elements, it is known to cover the flatbed with tarps. A tarp system can be used to secure the tarps to the flatbed to ensure optimal shipping conditions. A typical tarp system comprises a plurality of U-shaped frames that are flipped 180°, commonly referred to as bows, which are attached to the truck or trailer. The bows can be a one piece member or a modular member having two vertical side tubes and a horizontal center tube that are connected together using bracket assemblies. One or more tarps are attached to the bows to create an enclosed cargo area that is generally cube-shaped. The following examples of known tarp systems are provided as a general background.
U.S. Pat. No. 4,902,064 issued to Tuerk et al. discloses a Conestoga-style tarp system using bows that are attached to guide rails secured to sides of the flatbed. The rearmost bow is designed to be tilted or leaned to provide tension to the tarp and to secure the bow. The tarp is a single tarp, which is extended over the bows and supported by tension that is created by the positioning of the rearmost bow. The Tuerk tarp system does not disclose securing the tarp to the individual bows.
U.S. Pat. No. 5,538,313 issued to Henning discloses a tarp system for a flatbed trailer including a plurality of bow members for supporting the tarp. The bow members are slidably mounted to guide rails running along the sides of the flatbed, thus enabling the bow members to be moved to different locations on the flatbed and for the entire assembly to be compressed or expanded as required to load and unload the cargo. Henning is a modified version of the Tuerk system and similarly uses a single tarp supported by tension created by positioning of the bows. There is no disclosure of securing the tarps to the bows.
U.S. Pat. No. 5,080,423 issued to Merlot et al. discloses a segmented tarp cover system. The Merlot tarp system is designed as a series of segmented tarp pieces, which are extended to cover the top of a cargo container, such as a rail care or truck trailer. The Merlot tarp system is designed solely as a top covering and does not disclose any means or method of covering the sides and ends of a cargo container.
Fabricated bows become commonly used in tarp systems for the purpose of cost reduction and to help improve structural design integrity. Fabricated bows typically include a pair of vertical frame members and a central frame member that are welded together using corner fittings. However, the fabricated bows tend to require a large number of welds, which can be labor intensive. In addition, it has been found that the corner fittings at each side of the fabricated bow are critical and particularly troublesome to weld, which is especially true when the bows are made of aluminum.
To overcome these concerns, a tarp system was developed by DeMonte Fabricated Ltd. of Windsor, Ontario that uses modular bows for securing sections of tarp that respectively extend between the bows. The modular bows include a pair of vertical frame members and a central frame member that are connected together using aluminum cast corner fittings. Each modular bow defines a pair of longitudinal channels that extend along the peripheral surface of each bow and protrude outwardly therefrom. The channels are configured to receive support poles, which are provided along edges of the tarp. Further, the modular bows use aluminum castings for the corner fittings. However, it has been found that the DeMonte tarp system can be relatively difficult to assemble because the corner fittings do not completely secure the support poles inside the channels, and the corner fittings are relatively heavy.
U.S. Pat. No. 7,344,178 issued to Lowry et al. discloses a canopy structure for covering a trailer bed of a freight transport vehicle. The canopy structure includes a plurality of bows that are slidably secured to the trailer. The bows include a pair of vertical frame members and a horizontal frame member that are interconnected by corner assemblies. Each corner assembly has a central body portion and a pair of tongues that extend from each side of the central body portion for attachment with the frame members. Sections of tarp extend between the bows and are attached thereto using a tarp holder that is secured along the peripheral surface of each bow. The tarp holder defines a pair of longitudinal channels each configured to receive a beaded edge of the tarp. However, it has been found that the Lowry canopy structure is relatively difficult to assemble and not adequately durable for application on the road.
U.S. Pat. No. 7,931,326 issued to Beshiri et al. discloses a tarp system having tarp connectors for securing tarps to a vehicle. The tarp system includes modular bows having tarp connectors that are assembled together using corner connectors. The tarp connectors include a pair of channels that are configured to receive support poles provided along edges of adjacent tarps. Differently from the DeMonte tarp system described above, the channels provided in the Beshiri tarp system protrude toward an interior portion of the tarp connectors. The corner connectors are formed from two separate pieces that are joined together with bolts, outside and inside the tarp connector surfaces, to form a single piece connector. Each corner connector also defines a single, enlarged channel for receiving a pair of support poles of the tarp. However, it has been found that the Beshiri tarp system can decrease the working surface of the tarp connectors making their function and durability less than desirable. Also, the corner connectors do not have exclusive channels for the support poles. This can make it relatively difficult to insert and slide the support poles through the single channel at the corners and may also create a safety concern by damaging a portion of the tarp that is wrapped around the support poles. Furthermore, the durability of the corner connectors may be less than desirable.
The patents provided above demonstrate the open concerns and limitations of known tarps systems and modular bows. Thus, it would be desirable to provide a bracket assembly that is used to effectively and securely assemble modular bows in a sliding tarp system and to methods of assembling the same.